How many grams of calcium are in 3.01 x 1022 atoms of calcium?

The empirical formula of the compound (metal bromide) formed when 20.90 grams of chromium is heated in the presence of excess bromine is CrBr₂

First, we shall determine the mass of bromine in the compound. This is illustrated below

Mass of bromine = (Mass of compound) - (Mass of chromium)

Mass of bromine = 85.14 - 20.90

Mass of bromine = 64.24 grams

Haven obtained the mass of the bromine, we shall determine the empirical formula of the metal bromide. This is shown below:

Divide by their molar mass

Cr = 20.90 / 52 = 0.4

Br = 64.24 / 79.9 = 0.8

Divide by the smallest

Cr = 0.4 / 0.4 = 1

Br = 0.8 / 0.4 = 2

Thus, from the above calculation, the empirical formula of the metal bromide is CrBr₂

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The sodium-potassium pump goes to work after the contraction has occurred in order to repolarize the cells.

The sodium-potassium pump is a pump that functions in transporting sodium ions out of the cell and potassium ions inside the cell.

At the resting membrane potential, the sodium-potassium pump ensures that the interior of the cell is negative relative to outside the cell because three sodium ions are pumped out of the cell for every two potassium ions that are pumped into the cell.

When an action potential reaches the cell, the pump opens and allows sodium ions into the cell thereby depolarizing it. Afterward, the sodium-potassium pump works to repolarize the cell by pumping sodium out and potassium in.

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The molecular formula for Epsom salt is [tex]{ \blue{ \underline{ \tt{MgS O_{4} .7H_{2}O}}}}[/tex]

The concentration of the specie is obtained as  0.79 M.

We know that a buffer is a solution that is resistant to changes in acidity and alkalinity. Now, we know that we have the following information;

pH = 10.00

Concentration of base = 0.18 M

Kb = 4.4 x 10 -4

Hence;

pOH = 14 - 10.00 = 4

pKb = -log( 4.4 x 10 -4)  3.36

Using the formula;

pOH = pKb + log [A-/AH]

4 = 3.36 + log[A-/0.18]

4 - 3.36 = log[A-/0.18]

Antilog(4 - 3.36) = [A-/0.18]

A- = Antilog(4 - 3.36) * 0.18

A- = 0.79 M

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Ammonia is added to the test solution in a penny-earned lab to test the behavior of the reaction on a penny.

The cause of this Penny Lab is to determine how soap on a penny affects the figure of drops that it can hold, compared with a penny with no soap. Water molecules are impelled to each other, so they tend to try to stick together (cohesion). When a copper penny is heated in a solution of sodium hydroxide solution assorted with zinc dust, small amounts of zinc dissolve into the surface of the penny. This causes the penny to look silver already there is now a layer of zinc over the outside of the penny.

So we can conclude that  In this activity you will see that soap decreases the surface tension of water by satiuate water droplets on top of a penny.

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The food and agriculture industries' most complete carbon and net-zero route planner.

Coal, toxic gases, and crude oil—which are all used as fuel—are utilized to manufacture gasoline. It is employed to create a variety of products, such as polymers and steel, which is an alloy made of iron and carbon. Even black ink for printing and painting is produced with it.

The majority of carbon is kept in reservoir, or sinks, such rocks and sediments; the remaining portion is kept in the atmosphere, the oceans, and living things. Through the respiration of both plants and animals, carbon is returned to the atmosphere.

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Due to different structural compositions, humans and propane vary from one another.

Humans are made up of different elements than propane. For example, humans are made up of carbon, hydrogen, nitrogen, oxygen, and other trace elements, while propane is made up of carbon and hydrogen. This difference in composition leads to different properties. For example, humans are able to breathe and propane is not.

Humans and propane have different properties because they are made of different materials. Propane is made of hydrocarbons, while humans are made of cells.

The main difference between humans and propane is that humans are living while propane is not. This means that humans are made of cells that propane does not have. Additionally, humans breathe and have a circulatory system, while propane does not. Finally, humans are able to think and feel, while propane cannot.

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Answer:

If the dad has brown eyes, and the mom has blue eyes, then the kid will have blue eyes. If the dad has blue eyes and the mom has brown eyes, the kid will have brown eyes.

Explanation:

Answer: what the person above me said

Explanation:

The structural formula of the compounds from the task given above are as follows:

Methane, CH4: CH4CH4

Ethane, C2H6: (CH3)2

Propane, C3H8: CH3CH2CH3

Pentane, C5H12: CH3(CH2)3CH3

Hexane, C6H14: CH3(CH2)4CH3

A structural formula of an organic compound simply represent the various locations of atoms and bonds which makes up the organic compound.

It explains the exact point to fix bonds and atoms when writing the structural formula of a compound. That being said, organic compound simply refers to those classes of chemical compounds containing carbon and hydrogen.

They are different homologous families including the alkanes, alkenes, alkaynes, alkanols, alkanoates, alkanals and so on and so forth.So therefore, it can be deduced from the simple explanation above that the structural formula of compounds also enables us to clearly give the correct nomenclature of the compound.

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The net ionic equation for the reaction between copper and silver acetate is; [tex]Cu(s) + 2Ag^+ ====== > Cu^{2+} (aq) + 2Ag(s)[/tex]

The term net ionic equation has to do with the equation that shows the species that underwent a change in the reaction. As such, the ions that did not undergo a change does not appear in the net ionic equation for a given reaction.

In this case, what we have is the net ionic equation for the reaction between copper and silver acetate. We know that the silver ion is going to replace the silver so that we have;[tex]Cu(s) + 2Ag^+ ====== > Cu^{2+} (aq) + 2Ag(s)[/tex]

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Answer:

7

Explanation:

valence electrons are the electrons in the outer shell

State of matter of both substance will be liquid at 115C.

A substance-A substance's melting point is 100 degrees Celsius. Thus, liquid material A will arise from temperatures over 100 degrees. Since material A is liquid at 115 degrees Celsius, the particles are free to migrate and glide over one another.

B Substance-It has a  freezing point of 110 degrees Celsius. This signifies that substance B will exist in a liquid condition at any temperature greater than 110 °C. In a liquid condition, the components of solution B will also be sufficiently mobile to travel past one another.

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President Bush signed the Energy Policy Act in 2005 affect hydropower because Bush enacts the Energy Policy Act as law in an effort to address the rising energy issues. By offering tax breaks and credit guarantees for energy production of all kinds, including hydropower, the act altered American energy policy.

The revolutionary Architecture Hydraulique, written by French hydraulic and military engineer Bernard Forest de Bélidor, marked the beginning of the development of the modern hydropower turbine.

Note that the Energy Policy Act of 2005 was signed by President Bush on August 8, 2005. The Underground Storage Tank Compliance Act of 2005, Title XV, Subtitle B, amends Subtitle I of the Solid Waste Disposal Act, the primary law that established the underground storage tank (UST) program.

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Answer:

Explanation:

Coffee is a drink prepared from roasted coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content. It is the most popular hot drink in the world. Seeds of the Coffea plant's fruits are separated to produce unroasted green coffee beans.

Answer:

C

Explanation:

Water vapor is Earth's most abundant greenhouse gas. It's responsible for about half of Earth's greenhouse effect — the process that occurs when gases in Earth's atmosphere trap the Sun's heat.

Hope it made sense :)

Answer:

copper

Explanation:

First, write down the reaction and notice the ratio of moles of which the reactants react.

the equation (i'm too lazy to write states of matter and since it doesnt matter in this problem i'm not going to. it is balanced, however) is:
Cl2 + Cu -> CuCl2

as you can see, one mole of chlorine gas reacts with one mole of copper.

since we have 75 moles of copper but only 70 moles of chlorine gas, after everything has been reacted we would expect 5 moles of copper to be left over. so, copper is the the reactant which is in excess

Answer:

Basic

Explanation:

Solutions with a ph less than 7 are acidic, solutions with a ph greater than 7 are basic, and solutions with a ph equal to 7 are neutral.

The number of moles of the KClO₃ required to produce 5.15 moles of KCI is equal to 5.15 moles.

A mole can be described as a standard unit that is utilized to calculate the huge number of atoms, molecules, ions, or other particular particles. The mass of the 1 mole of any element is known as atomic mass and that of any compound is known as molar mass.

The number of units present in one mole is equal to 6.023 × 10 ²³ which is known as Avogadro’s constant or Avogadro’s number.

Given the chemical reaction of the decomposition of KClO₃ is :

2 KClO₃ ⟶  2KCl  +  3O₂

Given, the number of moles of KCl = 5.15 moles

As from the given  decomposition chemical reaction,

Two moles of the KCl are produced from moles of KClO₃ = 2

5.15 moles of  KCl are produced from KClO₃ = 5.15 mol

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11.29 grams of strontium-ninety had been gift withinside the unique rock pattern in 1933. Strontium- ninety decays to yttrium-ninety, which in flip decays to solid zirconium.

The isotopes of strontium and yttrium emit beta debris as they decay. The launch of radiation throughout this decay manner reasons situation approximately the protection of strontium and all different radioactive substances. Sr-ninety may be inhaled, however ingestion in meals and water is the best fitness situation. Once withinside the body, Sr-ninety acts like calcium and is effectively included into bones and teeth, wherein it may purpose cancers of the bone, bone marrow, and smooth tissues across the bone.

Strontium has a half-existence of 28.8 years. Therefore,

1989 - 1933 = 56years.

fifty six / 28.eight = 1.94 half-lives

Thus, the amount of the radioisotope closing will double for every half-existence elapsed. transferring backwards in time. Therefore, transferring backwards in time through 1.94 times half-lives, the amount closing will double through 1.94 times.

Thus, the quantity closing in 1933 is 3.0 × (1.ninety four)² = 11.29 grams.

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The correct balanced chemical equation is

[tex]\rm FeCl_2(aq) + 3NaOH(aq) \rightarrow Fe(OH)_3(s) + 3NaCl(s)[/tex]. Hence option A is correct.

Chemical equation is defined as the use of symbols and chemical formulas to represent a chemical reaction symbolically. Chemical equations give information about a compound's chemical make-up. The ratios in which the component parts combine to form the compound are also represented by them.

Balanced chemical equation is defined as entails giving the reactants and products stoichiometric coefficients. In a chemical equation, the number of atoms in the reactants and the number of atoms in the products must balance out.

Thus, the correct balanced chemical equation is

[tex]\rm FeCl_2(aq) + 3NaOH(aq) \rightarrow Fe(OH)_3(s) + 3NaCl(s)[/tex]. Hence option A is correct.

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The energy of the eight shell of the hydrogen atom is obtained 0.2 eV

We know that from the Bohr model, the electrons that are in an atom can be arranged in energy levels. The energy levels of the atom are arranged in such a way that the levels that are lowest in energy are found nearer to the nucleus and the energy of the shells continue to increase outwards.

Thus, the energy of the eight shell would be much more than the energy of the first shell. Let us consider the formula;

E = - 13.6Z^2/n^2

Where;

Z = atomic number of the atom

n = The shell where the electron is

Thus;

E = - 13.6 * 1/8^2

E = -0.2eV

Thus the energy that an electron that we can find in the shall that has n = 8 would have the energy that is equivalent to 0.2eV.

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Answer:

The answer is 10.507 KJ

Explanation:

The formula you need to use for this question is MC(delta)T:

M=Mass ( 175g)

C=Specific Heat ( depends on the element, copper=0.38 j/g.k )

and T= Temperature, where you find the change in temperature by minusing the final T with the initial T.  

so, (175g)(0.38)(184-26)= 10,507 J

since we need the answer in KJ divide 10,507 by 1000

10,507/1000 = 10.507 KJ

Explanation:

These soft areas are the gaps between the skull's bones, when bone growth hasn't finished. As a result, the skull can be shaped during birth. By the age of two to three months, the smaller spot at the back usually closes. Around age 18 months, the larger spot in the front frequently closes.

AnswerNegative Partial Charge on: Se, O, O. O-Te is most polar.

Explanation:

O, Se, and Te are all in the same group on the periodic table, which makes this question easier because there is a periodic trend for electronegativity going up and down groups. The more you go down the periodic table, the more shielding affect there is where the electrons closest to the nucleus of an atom block the protons’ positive charge from reaching other electrons. So, O is the most electronegative here, followed by Se, and then Te. So in a bond with O and either of the other two, O will always have a partial negative charge. Se in a bond with Te will also have a partial negative charge, but the difference in electronegativity is biggest between O and Te, and so that is the most polar bond.

According to the electronic configuration and difference in electronegativity, the most polar bond is O-Te.

Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.

Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.

Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.

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Answer:

2

Explanation:

Because both atoms ate from the same element, iron

Answer:

Below

Explanation:

Mole wt:

cu = 63.546

c x 2 =24

hx6=6

0 x 4 =64    total per mole = 157.546

Number of moles * Avagadro's Number  = number of molecules

    80 / 157.546     *  6.022 x 10^23 = 3.06 x 10^23 molecules

The volume of gas produced at 18 degrees Celsius 34.7 g of carbon dioxide gas creates of 623 mmHg is 0.03 L

The ideal gas equation is as follows;

PV=nRT

P,V,n,R,T are pressure, volume, number of moles, gas constant and temperature respectively

Substituting the values, we get

623xV=34.7/44x0.0821X291

623V=0.78X23.8911

623V=18.635

V=0.03 L

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The reaction as is shown in option E has its enthalpy of reaction not the same as the enthalpy of formation of the product.

The enthalpy of formation is the heat that is evolved or absorbed when a substances is formed from its constituents under standard conditions. We know also that the enthalpy of the reaction is the heat that is evolved or absorbed in the reaction.

In a case where we know that the compound which is obtained in the product is not formed from the substances that are in their standard states, it the follows that the enthalpy of the reaction would not be the same as the enthalpy of formation of the product.

This is so because, the enthalpy of formation of the standard substances is always zero. Given the fact that both Xenon atom and the fluorine gas are pure substances in standard state, their enthalpies of formation are zero thus the enthalpy of formation of the xenon fluoride is the same as the enthalpy of the reaction. Option E.

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